Data engineering·Governance, privacy and meaning
the user id is replaced with a hash so you can still count sessions per person, and rejoining it to a name is a deliberate act with a key.
Pseudonymisation
Also calledhashed identifiers, keyed pseudonyms
Replacing identifiers with consistent substitutes so behaviour can still be linked per person without the person being named. It preserves the analytical joins that matter while removing the direct identifier. Most privacy regimes treat it as still personal data, because the mapping exists — which is the distinction people most often get wrong when they claim a dataset has been anonymised.